Chair with a tilting seat

ABSTRACT

A chair with a tilting seat, comprising a monocoque structure including a seat and a backrest formed as a single piece of injection-molded plastic material, wherein the monocoque structure comprises at least one bellows-shaped deformable transverse band formed as one piece in the backrest, so as to divide the backrest into a lower backrest portion fixed relative to the seat and an upper backrest portion movable relative to the lower backrest portion between a rest position and a tilted position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of Italian patent application number 102015000006504, filed Feb. 17, 2015, which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a chair comprising a seat and a backrest, in which the backrest is tiltable backwards relative to the seat under a backward thrust applied by the user.

2. Description of Prior Art

In the state of the art, many chairs are known with backrests that are tiltable under a backward thrust applied by the user. The document EP-A-14196090.6 by the same Applicant describes a chair comprising a fixed support structure including a pair of front legs and a pair of rear legs, a seat, fixed to the fixed support structure, and a backrest with a backrest panel with an arcuate shape connected in an oscillating manner to the fixed support structure. The backrest comprises two side connecting elements of plastic material, each of which comprises a cylindrical sleeve fixed to an upper portion of a respective rear leg. The side connecting elements of the backrest have respective bellows-shaped deformable portions, integrally formed with the respective cylindrical sleeve. The bellows-shaped deformable portions are connected in a fixed manner to respective side portions of the backrest panel.

Monocoque chairs are characterized by a monolithic structure in which the seat and backrest are formed as a single molded panel of plastic material. Monocoque chairs do not usually have backwardly-tiltable backrests.

SUMMARY OF THE INVENTION

The present invention aims to provide a monocoque chair equipped with a tiltable backrest.

According to the present invention, this object is achieved by a chair having the characteristics forming the subject of claim 1.

The claims form an integral part of the disclosure provided here in relation to the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described in detail with reference to the attached drawings, given purely by way of non-limiting example, wherein:

FIG. 1 is a perspective view of a monocoque chair according to the present invention.

FIG. 2 is a rear perspective view of the chair of FIG. 1.

FIG. 3 is a perspective view on an enlarged scale of the part indicated by the arrow III in FIG. 1.

FIG. 4 is a cross-section along the line IV-IV of FIG. 1.

FIGS. 5 and 6 are longitudinal cross-sections of the chair of FIG. 1, in the rest position and in the backward-tilted position, respectively.

FIG. 7 is a perspective view illustrating a variant of the chair of FIG. 1.

DETAILED DESCRIPTION

With reference to the figures, numeral 10 designates a chair according to the present invention. The chair 10 comprises a base 12, which carries a monocoque structure 14 in which a seat 16 and a backrest 18 are formed as a single panel of injection-molded plastic material essentially in the shape of an L.

In the illustrated example, the base 12 has two front legs 20 and two rear legs 22 fixed to each other by an upper structure 24 to which the monocoque structure 14 is fixed. Alternatively, the base 12 could have a rotatable central column. In general, the base 12 can be of any type.

The monocoque structure 14 including the seat 16 and the backrest 18 is obtained as a single piece of injection-molded plastic material, for example nylon. The monocoque structure 14 comprises a bellows-shaped deformable transverse band 26, which extends in the transverse direction between two opposite side edges 28 of the seat 18. The deformable transverse band 26 is integrally formed with the monocoque structure 14 during the injection-molding step and is formed as one piece with the backrest 18. The deformable transverse band 26 divides the backrest 18 in the transverse direction into a lower backrest portion 18 a and an upper backrest portion 18 b. The lower backrest portion 18 a is connected as a single piece with the rear portion of the seat 16.

The upper backrest portion 18 b is movable backwards with respect to the lower backrest portion 18 a between a rest position and a backward-tilted position. The backward movement of the upper backrest portion 18 b under a backward thrust applied by the user's back is possible thanks to the elastic deformation of the deformable transverse band 26.

With reference in particular to FIGS. 3 and 4, the deformable transverse band 26 comprises a plurality of transverse ribs 30 with C-shaped cross-sections, each of which extends in the transverse direction between the opposite side edges 28 of the backrest 18. The transverse ribs 30 are connected to each other at their ends and alternately face towards the front part and towards the rear part of the chair. In the example shown, the deformable transverse band 26 comprises three transverse ribs 30. The upper rib and the lower rib have the respective concave part facing towards the front of the chair and a central rib that joins together the upper rib and the lower rib, and has the concave part facing the rear part of the chair.

FIGS. 5 and 6 are longitudinal cross-sections showing the chair 10 in the rest position and in the backward-tilted position, respectively. The deformable portion 26 allows the backward tilt of the upper backrest portion 18 b relative to the lower backrest portion 18 a. When the backward thrust applied by the user ceases, the deformable transverse band 26 elastically returns to its undeformed position and returns the backrest 18 to the rest position illustrated in FIG. 5. The same deformable transverse band 26 also forms a stop which prevents any further backward movement of the upper backrest portion 18 b beyond the position of maximum backward inclination illustrated in FIG. 5. In fact, as shown in FIG. 6, when the upper backrest portion 18 b is tilted backwards, the outer side parts of the bellows-shaped deformable transverse band 26 open, or rather the distance between the transverse ribs 30 increases, while the central part of the deformable transverse band 26 closes, that is, the ribs 30 come into contact with each other. In particular, when the convex parts of the upper rib and the lower rib are compressed into contact with each other, further elastic deformation of the deformable transverse band 26 is prevented. Therefore, in this condition, further backward inclination of the upper backrest portion 18 b is prevented.

In the embodiment illustrated in the figures, the backrest 18 comprises a single deformable transverse band 26. Alternatively, more deformable transverse bands could be provided, spaced apart in the vertical direction. If the deformable transverse bands are of a number greater than one, they could be distributed along the backrest 18.

It is not strictly necessary that the deformable transverse band 26 extends continuously between the opposite side edges 28 of the backrest 18. In fact, as shown in FIG. 7, the backrest 18 could be provided with a through-opening 32, which interrupts the deformable transverse band 26 in the transverse direction. The opening 32 visually separates the backrest 18 from the seat 16 and provides a visually lighter chair, with an elastic behavior more easily deducible by the user.

Of course, without prejudice to the principle of the invention, the details of construction and the embodiments can be widely varied with respect to those described and illustrated, without thereby departing from the scope of the invention as defined by the claims that follow. 

1. A chair with a tilting seat, comprising a monocoque structure including a seat and a backrest formed as a single piece of injection-molded plastic material, wherein the monocoque structure comprises at least one bellows-shaped deformable transverse band formed as one piece in the backrest, so as to divide the backrest into a lower backrest portion fixed relative to the seat and an upper backrest portion movable relative to the lower backrest portion between a rest position and a tilted position.
 2. A chair according to claim 1, wherein the deformable transverse band extends between two opposite side edges of the backrest.
 3. A chair according to claim 1, wherein said deformable transverse band comprises a plurality of transverse ribs with a C-shaped cross-section, parallel to each other, with respective concavities alternately facing towards the front and towards the rear of the chair.
 4. A chair according to claim 1, wherein said deformable transverse band forms a stop that prevents a further backward motion of the backrest in a position of maximum backward inclination.
 5. A chair according to claim 1, comprising at least one opening in the backrest, which interrupts said at least one deformable transverse band in a transverse direction. 